Effectiveness of Methanol Extracts from Mexican Leaf (Tithonia diversifolia) and Jicama Seeds (Pachyrhizus erosus) in Controlling Silverleaf Whitefly (Bemisia tabaci) on Tomato Plants.

<b>Background and Objective:</b> Silverleaf whitefly (<i>Bemisia tabaci</i> ) is one of the most notable pest attacks on tomato plants. A viable eco-friendly option for pest control involves using pesticides specifically derived from the methanol extracts of <i>Tithonia diversifolia</i> and <i>Pachyrhizus erosus</i>. This study aims to determine the concentration of methanol extracts from <i>T. diversifolia</i> leaves and <i>P. erosus</i>. <b>Materials and Methods:</b> The study employed a Randomized Complete Block Design (RCBD) with 9 treatments and 3 replications. The toxicity of various extract concentrations was assessed through probit analysis, while plant growth and pest population density were monitored across multiple stages, with manual spraying of the extracts. This study uses a controlled greenhouse environment and detailed monitoring of environmental conditions, plant height and pest density throughout the two-week treatment period. A one-way ANOVA was conducted to evaluate differences between treatment groups, with significance set at p<0.05. <b>Results:</b> The LC₅₀ and LC₉₅ values for <i>T. diversifolia</i> leaf methanol extract at 3.8 and 7.9 g/L, respectively. The LC₅₀ and LC₉₅ values for <i>P. erosus</i> seed methanol extract were 4.3 and 8.7 g/L, respectively. The toxicity test results of both extracts have relatively high LC₅₀ and LC₉₅ values, indicating moderate toxicity levels. The most significant reduction in nymph population density occurred with the highest concentrations in <i>T. diversifolia</i> leaf (15.9 and 23.9 g/L) and <i>P. erosus</i> seed (17.4 and 26.2 g/L) extracts. In addition, both of the extracts can enhance tomato fruit height and harvest yield. <b>Conclusion:</b> Methanol extracts of <i>T. diversifolia</i> leaves and <i>P. erosus</i> seeds effectively reduce the <i>B. tabaci</i> population on tomato plants, with the highest suppression (100%) observed at concentrations of 15.9 g/L for <i>T. diversifolia</i> leaves and 26.2 g/L for <i>P. erosus</i> seeds, leading to increased fruit production compared to the control.